My father-in-law is in his 70s. He built a new house in 2016. He's a builder so he could do almost all of the work himself (apart from electrical and heating) w

My father-in-law is in his 70s. He built a new house in 2016. He's a builder so he could do almost all of the work himself (apart from electrical and heating) with two hired helpers. The concrete was poured by a company. The roof trusses were designed and premanufactured, then delivered to site and installed by him and his guys. I think he had someone come in for some tiling jobs. Other than that, it was all off-the-shelf material. All in, he spent around $300k including the plot. Then COVID happened. Now, similar houses on his street sell north of 800k.